Reworked DatabaseService API.
Initial implementation of LockManager.
diff --git a/core/api/src/main/java/org/onlab/onos/store/service/WriteRequest.java b/core/api/src/main/java/org/onlab/onos/store/service/WriteRequest.java
index fb736e5..6607cfe 100644
--- a/core/api/src/main/java/org/onlab/onos/store/service/WriteRequest.java
+++ b/core/api/src/main/java/org/onlab/onos/store/service/WriteRequest.java
@@ -112,7 +112,7 @@
      * @param previousVersion previous version expected
      * @return WriteRequest
      */
-    public static WriteRequest remove(String tableName, String key,
+    public static WriteRequest removeIfVersionMatches(String tableName, String key,
                                       long previousVersion) {
         return new WriteRequest(REMOVE_IF_VALUE, tableName, key,
                                 null, previousVersion, null);
@@ -127,7 +127,7 @@
      * @param oldValue  previous value expected, must not be null
      * @return WriteRequest
      */
-    public static WriteRequest remove(String tableName, String key,
+    public static WriteRequest removeIfValueMatches(String tableName, String key,
                                       byte[] oldValue) {
         return new WriteRequest(Type.REMOVE_IF_VALUE, tableName, key,
                                 null, ANY_VERSION, checkNotNull(oldValue));